This isn't quite the way you get your GPA. Let me try and break it down by course average, lesson average, and GPA.
To find your course average, you simply add up all of your scores for the exams in the course and then divide by the number of exams. Your overall lesson average gives you an idea of how you are doing overall, for everything you've submitted in the entire program so far. Your course averages, in my opinion, are more helpful in tracking your progress.
When we figure out a GPA, the number of credits earned on each grade range (A, B, C, and D) are counted and tallied. You receive 4 points for every A, 3 for every B, 2 for every C, and 1 for every D. You count up the total amount of points that you’ve received and divide it by the total amount of credits earned. This will give you your GPA. Therefore, if every credit you earned was within the A range, then you would receive a 4.0. If every credit you earned was within the B range, then you would receive a 3.0. In most cases, people get a mixtures of grades (some As, Bs, etc.) and fall within a range. For example, if someone got half A grades and half B grades, they'd most likely end up with a 3.5.
Unfortunately, we don't calculate GPAs until the end of the program. However, a Google search should bring up many GPA calculators, such as http://www.calculator.net/gpa-calculator.html. Each course is worth 1 credit except for Orientation, which is worth 0.5 credit.
The link to this information can be found below so you can read more about it: